The invention pertains to methods and apparatuses for sensing changes in an environment, and in particular applications pertains to methods and devices for sensing termites.
A prior art apparatus and method for detecting termite infestation is described with reference to FIGS. 1 and 2. A termite detection device 10 is shown in an assembled configuration and inserted within the ground 12 in FIG. 1, and is shown in a disassembled configuration in FIG. 2. Device 10 comprises an outer receptacle 14 having a plurality of orifices 16 (only some of which are labeled) extending therethrough. A cap (or lid) 18 is provided to cover the top of receptacle 14. Preferably receptacle 14 is inserted into the ground to a depth at which cap 18 will rest approximately at a surface of the ground.
A pair of wooden blocks 20 and 22 are provided within receptacle 14, and constitute xe2x80x9cbaitxe2x80x9d for termites proximate device 10. A holder 24 is provided between blocks of wood 20 and 22 and comprises a shelf 26 upon which blocks 20 and 22 rest. Holder 24 and blocks 20 and 22 together comprise an assembly 27 which can be removably inserted into receptacle 14.
Holder 24 comprises a portion 28 which protrudes upwardly beyond blocks 20 and 22 in the assembled configuration of FIG. 1. Portion 28 comprises an eye 30 (shown in FIG. 2) which can simplify removal of assembly 27 from receptacle 14 using a tool with a hook.
In operation, receptacle 14 is inserted into ground 12, and blocks 20 and 22 are subsequently left in receptacle 14 for a period of time. Blocks 20 and 22 function as a sensing apparatus to determine if a termite infestation is present in an area proximate device 10. Specifically, if termites are present, such will penetrate through orifices 16 to reach wooden blocks 20 and 22. The termites will then burrow into the wooden blocks 20 and 22.
At regular intervals, cap 18 is removed and blocks 20 and 22 withdrawn from device 14. Blocks 20 and 22 are then surveyed for termite-inflicted damage, and possibly the presence of termites themselves.
Generally, a number of apparatuses 10 will be spread around a given location, such as, for example, a house or other wooden structure. Each of the apparatuses will be checked at a regular interval to determine if a termite infestation is occurring proximate the structure. Also, each of the devices will be mapped relative to one another, and relative to the structure. A comparison of the amount of termite-inflicted damage occurring at the respective devices 10 can then enable a person to determine an approximate localized region of any occurring termite infestation. It can be advantageous to pinpoint a localized region of infestation as such can limit an amount of pesticide utilized for destroying the termites.
Difficulties can occur in monitoring the amount of termite-inflicted damage occurring at each of the many devices 10 provided around a structure. For instance, it can be difficult to regularly and accurately document the amount of damage at each of the devices. As an example, it can be difficult to remember exactly which of the various devices correlates to a specific location on a map of the devices. As another example, it can be difficult to accurately record a reading of termite-inflicted damage associated with an individual device. As yet another example it can be tedious and time-consuming to open all of the receptacles 14 proximate a given structure and manually check the blocks 20 and 22 within the receptacles for termite-inflicted damage.
One method of reducing the above-discussed difficulties is to provide bar codes on the lids 18 of receptacles 14. Such bar codes can be scanned to specifically identify a particular device which can simplify correlating the devices to locations on a map of the devices. However, ascertaining an amount of termite-inflicted damage can still be time-consuming in that the receptacles still have to be opened and the blocks of wood manually checked to determine if termite-inflicted damage has occurred to the wood.
A recently proposed improvement for monitoring an amount of termite-inflicted damage in a device similar to device 10 is described with reference to FIGS. 3-5. Referring to FIG. 3, a sensor 40 having circuitry 41 provided thereon is provided in addition to, or in place of, the blocks of wood 20 and 22 (FIGS. 1 and 2). Sensor 40 is intended to be bent into receptacle 14 (a bent configuration is shown in FIG. 4) and to be configured such that termite-inflicted damage to sensor 40 will break the circuitry associated therewith. Sensor 40 can have a number of notches (not shown) provided therein to provide crevices for termites to burrow in.
It is suggested that a printed wiring board 42 can be provided in electrical connection with sensor 40, and that such printed board can comprise circuitry corresponding to a transponder unit. The transponder unit could, for example, comprise a parallel resonant LC circuit, with such circuit being resonant at a carrier frequency of an interrogator. Such transponder unit can be incorporated into a passive, read-only radio frequency identification device (RFID) system as described with reference to FIG. 5. Specifically, FIG. 5 illustrates an RFID system 60 comprising the transponder unit of printed wiring board 42 and an interrogator 45 configured to be passed over transponder unit 42. Interrogator 45 comprises a coil antenna configured to stimulate the transponder unit. Such coil antenna consists of one or more coils of conductive material provided within a single plane, and can be in the form of, for example, a loop antenna.
In operation, interrogator 45 provides a carrier signal which powers (stimulates) transponder unit 42 and causes a signal to be transmitted from the transponder unit. The signal comprises data which identifies the transponder unit. Such signal can also identify if the circuitry associated with sensor 40 has been broken. The signal is received by interrogator 45, and eventually provided to a processing system configured to decode and interpret the data. Such processing system can be provided in a portable unit with interrogator 45, or can be provided in a separate unit to which data from interrogator 45 is subsequently downloaded.
In one aspect, the invention includes a device for sensing a change in an environment proximate the device. The device comprises a loop of conductive material. The conductive material comprises two ends and the loop is configured to be broken upon the change in the environment. The device further comprises a pair of prongs. A first of the pair of prongs extends from one of the two ends of the conductive material and a second of the pair of prongs extends from an other of the two ends of the conductive material. Additionally, the device comprises a circuit support having circuitry supported thereby and a pair of orifices extending therethrough. The prongs extend through the orifices to electrically connect the circuitry supported by the circuit support to the loop of conductive material.
In another aspect, the invention includes a device for sensing termites. The device comprises at least two wooden blocks and a planar loop of conductive material between the wooden blocks. The planar loop extends along a first plane. The conductive material comprises two ends. The wooden blocks and planar loop of material form a composite block having an outer periphery. The device further comprises a pair of prongs. A first of the pair of prongs extends from one of the two ends of the conductive material and a second of the pair of prongs extends from an other of the two ends of the conductive material. The first and second prongs extend outwardly beyond the outer periphery of the composite block. The device further comprises a circuit support having circuitry supported thereby and a pair of orifices extending therethrough. The prongs extend through the orifices to electrically connect the circuitry supported by the circuit support to the planar loop of material.
In yet another aspect, the invention includes a method for sensing termites. A sensing device is formed from at least two wooden blocks and a planar loop of conductive material between the wooden blocks. The planar loop extends along a first plane and comprises two ends. The wooden blocks and planar loop of material form a composite block having an outer periphery. The conductive loop is formed of a material that can be removed by termites. The sensing device also comprises a pair of prongs. A first of the pair of prongs extends from one of the two ends of the conductive material and a second of the pair of prongs extends from an other of the two ends of the conductive material. The first and second prongs extend outwardly beyond the outer periphery of the composite block. Additionally, the sensing device comprises a circuit support having circuitry supported thereby and a pair of orifices extending therethrough. The prongs extend through the orifices to electrically connect the circuitry supported by the circuit support to the planar loop of material. The circuit support comprises at least a portion of a transponder unit configured such that a break in the conductive loop alters a signal transponded by the transponder unit. The sensing device is placed in the ground. The signal transponded by the transponder unit is monitored to determine if the conductive loop is broken.